Various ablative therapies such as radio-frequency, microwave and laser ablation can be used to treat benign and cancerous tumors. In theory, such methods are intended to produce physiological and structural changes to cause cell necrosis or destruction of the selected target tissue. However in practice, there are numerous difficulties in the use of ablative procedures to treat cancerous tissue, these include (i) locating the target tissue, (ii) identifying or biopsying the disease state of the tumorous tissue (iii) distinguishing between diseased tissue versus healthy tissue, (iii) placing and maintaining the position of the ablation apparatus within the target tissue site, (iv) monitoring the progress of ablation including the developing ablation volume, (v) minimizing injury to adjacent critical structures (vi) assuring complete ablation of the tumor mass including assurance of a sufficient healthy tissue margin and (vii) assessing degree of the completed ablation. Current ablative therapies have not considered nor provided solutions to these problems. Thus, there is a need for an apparatus and method to address these difficulties and other unmet needs in performing ablative therapies for the treatment of cancer, tumors and other diseases.